Can someone give an example of an operational amplifier whose positive and negative slew rates are different from each other? I have searched for it in the book Design of Analog CMOS Integrated Circuits, but I could not find one.
\$\begingroup\$
\$\endgroup\$
2
-
\$\begingroup\$ I've never seen one from what I remember. Maybe you should explain why you think one is of interest to you? \$\endgroup\$– Andy akaNov 21, 2022 at 16:46
-
\$\begingroup\$ Confirmed. Statistically "equal". \$\endgroup\$– Antonio51Nov 21, 2022 at 16:48
Add a comment
|
1 Answer
\$\begingroup\$
\$\endgroup\$
3
Yes, the LT1056. Asymmetry can be ~2:1 for this type of op-amp.
A case in point is that of the available P-channel JFET input op amps, many which have a characteristic SR response which is asymmetrical. In fact, popular op amps with topologies like the original 355/356 types are intrinsically faster for negative going output swings than they are for positive. Similar comments apply to such related devices as the OP15, OP16, etc. Since this type of JFET device topology was introduced, the SR specifi ed on the data sheet has typically been the lower of two dissimilar rates, i.e., the slower, positive edge SR. Thus, given an op amp with a typical SR spec of 14V/μs for positive going edges, the same amp will have a corresponding negative SR of about 28V/μs
answered Nov 21, 2022 at 17:15
-
\$\begingroup\$ And what are the "benefits" of such dissymmetry? \$\endgroup\$ Nov 21, 2022 at 17:19
-
1\$\begingroup\$ @Antonio51 There might be some in a nonlinear circuit, but I think it's just a characteristic of that type of part that you have to live with. \$\endgroup\$ Nov 21, 2022 at 17:28
-
\$\begingroup\$ Ok. I guess it is only in fast "circuits" that this can happens ... \$\endgroup\$ Nov 21, 2022 at 17:35